Sumbul Rais

Hydrochemical investigation and quality assessment of ground water in rural areas of Delhi, India

The suitability of groundwater quality for drinking and agricultural purposes was assessed in the rural areas of Delhi based on the various water quality parameters. A total of 50 ground water samples were collected randomly from different sources viz. hand pump, tube well, boring and analyzed for major ion chemistry to understand the operating mechanism of geochemical processes for ground water quality. The quality analysis is performed through the estimation of pH, EC, TDS, total hardness, total alkalinity, Na, K, Cl, NO3, SO4, DO, BOD, Cu, Cr, Cd, Ni, Zn and Pb. Hydrochemical facies were identified using Piper, Durov and Chadha diagram. Chemical data were also used for mathematical calculations (SAR, %Na, RSC, PI, KI, and chloroalkaline indices) for better understanding the suitability of ground water for irrigation purposes. The results of saturation index shows that all the water samples were supersaturated to undersaturated with respect to carbonate minerals and undersaturated with respect to sulphate and chloride minerals. According to USSL diagram, most of the samples fall in the field of C3S1, indicating medium salinity and low sodium water which can be used for almost all types of soil with little danger of exchangeable sodium. Assessment of water samples from various methods indicated that majority of the ground water in the study area is chemically suitable for drinking and agricultural uses.

Adsorption of Hg(II) from Aqueous Solution Using Adulsa (Justicia adhatoda) Leaves Powder: Kinetic and Equilibrium Studies

The ability of Adulsa leaves powder (ALP) to adsorb Hg(II) from aqueous solutions has been investigated through batch experiments. The ALP biomass was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental parameters that were investigated in this study included pH, adsorbent dosage, and effect of contact time along with initial metal ion concentration. The adsorption process was relatively fast, and equilibrium was achieved after 40 min of contact time. The maximum removal of Hg(II), 97.5% was observed at pH 6. The adsorption data were correlated with Langmuir, Freundlich, and Temkin isotherms. Isotherms results were amply fitted by the Langmuir model determining a monolayer maximum adsorption capacity () of ALP biomass equal to 107.5 mg g−1 and suggesting a functional group-limited sorption process. The kinetic process of Hg(II) adsorption onto ALP biomass was tested by applying pseudofirst-order, pseudosecond-order, Elovich, and intraparticle-diffusion models to correlate the experimental data and to determine the kinetic parameters. It was found that the pseudosecond order kinetic model for Hg(II) adsorption fitted very well. The rate determining step is described by intraparticle diffusion model. These studies considered the possibility of using Adulsa plant leaves biomass as an inexpensive, efficient, and environmentally safe adsorbent for the treatment of Hg(II) contaminated wastewaters.

Detection of Atrazine and Simazine in Ground Water of Delhi using High Performance Liquid Chromatography with Ultraviolet Detector

Herbicide usage has increased dramatically during the last two decades coinciding with the change in farming practices and increasingly intensive agriculture. This study thus assesses herbicide occurrence in the ground water of Delhi i.e. Atrazine and Simazine herbicide. Liquid-liquid extraction with dichloromethane and methanol as extracting solvents were used. These extracted herbicides were separated and quantified by High Performance Liquid Chromatography (HPLC) with ultraviolet detector. The excellent results were achieved with spiked recoveries of 96.8% and 84.6 % for atrazine and simazine respectively. Analysis shows that the concentration of simazine was higher as compared to atrazine. The results obtained were compared with WHO limit of 0.002 mg/l and USEPA limit of 0.003 mg/l for Atrazine and 0.004 mg/l for Simazine. Highest concentration of atrazine was recorded in the north region of Delhi. Sample from the central Delhi did not reveal contamination from any of the herbicides being monitored. The results indicate that there is need for further work to identify sources and fate of herbicide contaminations. The findings of our investigation contribute to the knowledge of the extent of pollution in the groundwater of Delhi.

Hydro-chemical Survey of Groundwater of Delhi, India

The physicochemical parameters and trace metal contents of water samples from Delhi were assessed. A total of 20 water samples were collected from boring, tube well and hand pump and analyzed for the various physicochemical parameters like pH, conductivity, total dissolved solid, total alkalinity, Ca2